Reversible counting apparatus



Filed April 24. 1956 3 Sheets-Sheet l INVENTOR.

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' REVERSIBLE COUNTING APPARATUS Filed April 24. 1956 3 Sheets-Sheet 3 INVENTOR. Dan L'el Pouze.

H15 HTTOH/VEY United States Patent REVERSIBLE COUNTING APPARATUS Daniel Pouzet, Sevran, France, assignor to Compagnie des Freins et Signaux Westinghouse, Paris, France Application April 24, 1956, Serial No. 580,222

Claims priority, application France April 26, 1955 Claims. (Cl. 235-92) This invention relates to counting apparatus and particularly to an improved reversible electronic counting chain adapted to indicate the accumulated algebraic sum of add and subtract pulses received over separate input transformers.

In telecommunication, remote control, computing and signaling, the problem frequently arises of counting or registering serial impulses, and in many cases it is required to register or indicate the accumulated algebraic total of signed impulses. Counting devices are known which have been used for various purposes in these fields, 'but such devices have generally included relays, movable parts, or rotating or step-by-step commutators, which present certain complications and difiiculties in installation and operation. Accordingly, it is an object of the present invention to provide a reversible counting device which is fully electronic and incorporates no moving parts.

It is a further object of my invention to provide a reversible electronic counting apparatus which utilizes a minimum number of electronic tubes.

It is a further object of my invention to provide a reversible electronic counting apparatus comprising a plurality of counting chains corresponding to successive orders of magnitude and improved pulsing means for applying adding or subtracting counting impulses to such chains in such a manner that the counting chain for a given order of magnitude will complete a cycle of operation for each step of operation of the next higher order counting chain.

Other objects and further advantages of my invention will become apparent to those skilled in the art as the description proceeds.

In carrying out the above and other objects of my invention, according to one embodiment of my invention I provide an arrangement for counting in a given number system comprising a number of electronic tubes for each order of magnitude to be considered corresponding to the number of signs of the numerical system in question for each order of magnitude (10 for a decimal system, 2 for a binary system, 3 for a ternary system, etc.), two charging resistances in series, one in the circuit of the anode of each tube, the other in the circuit of the cathode, and means for supplying the assembly of the tubes from a source of direct current in series with the charging resistances. I further provide means for cutting off preceding or succeeding tubes upon the energization of a given tube, comprising anode capacitors located between anodes of the consecutive tubes and cathode capacitors located between cathodes of the consecutive tubes.

According to another feature of my invention, each of the tubes in a counting chain includes a control circuit comprising preparing elements for applying to each grid circuit a potential forming an essential part of the amplitude necessary for firing the tube, and pulsing elements for applying to each grid circuit successively an impulse controlling the progression or the retrogression of the counting chain. A further feature of one form of my invention is that the previously described preparing elements in the grid circuits of each tube comprise components of asymmetric or unidirectional conductivity connected in an opposite manner with respect to each other in each of the connections between cathodes and grids of the successive tubes.

In a particular embodiment of my invention, the pulsing elements connected in each grid circuit are made up of windings mounted in series with the connections between the cathodes and grids of the tubes whereby these windings form independent secondaries of an impulse transformer fed by a generator of progressive or retrogressive impulses.

According to a further feature of one embodiment of my invention, for each order of magnitude higher than the first a magnetic circuit is provided which comprises a primary Winding on a saturable core fed in a permanent manner and bringing the point of operation of the circuit to rest in saturation, a secondary Winding fed in a similar manner as the primary of the previously mentioned impulse transformer, a third Winding in series in the anodic or cathodic circuit of the first or last tube of the series of tubes corresponding to the order of magnitude under consideration, and finally a series of receiver windings connected to the tubes of the order of magnitude under consideration in the same manner as the secondaries of the before-mentioned impulse transformer are connected to the tubes corresponding to the first order of magnitude.

A further feature of one embodiment of my invention comprises the provision of two impulse transformers for the first order of magnitude, one corresponding to the impulses in the progressive direction and the other to the impulses in the retrogressive direction, and furthermore, for each order of magnitude higher than the first, two magnetic circuits as defined above, one for the progressive operation of the meter and the other for the retrogressive operation.

i shall first describe one embodiment of my invention, and shall then point out the novel features thereof in claims.

Figures 1a and 1b, when arranged horizontally with Fig. la at the top, comprise a wiring diagram of one embodiment of my invention.

Fig. 2 is a graph showing the operation of the circuit of Figures 1a and 1b.

Referring to Figures 1a and 1b, a three decade reversible counter for use in the decimal number system is shown. Ten electronic tubes are provided for each decade. As shown, these tubes may be cold cathode thyratrons, but it will be apparent to those skilled in the art that other electron discharge devices could be employed without departing from the broader aspects of my invention.

The tubes employed for each decade are arranged to form a continuous reversible counting ring. For the units decade, tubes U4} through U9 are provided. Since the circuits for tubes U3 through U7 would merely repeat the circuits for the tubes shown, they have been omitted for the sake of simplicity and clarity. The tens decade of the counter comprises tubes T0 through T9, and the hundreds decade comprises tubes H0 through H9. Each of the counting chains thus formed is adapted to be energized in a progressive or retrogressive direction by impulses in a manner to be described.

A source of adding, of progressive, impulses is shown schematically at P. Since the details of this source form no part of my present invention, they are not shown. However, it is obvious that any suitable means for providing a pulse of voltage for each event to be added, such as a pulsing transformer or a manually operable key, could be employed for this purpose. Similarly, a source R of retrogressive or subtractive impulses is rs shown in block form. These impulses are transmitted to the various orders of the counting apparatus through transformers UP, UR, TP, TR, HP, and HR, through circuits to be described.

Referring now to the first decade counting chain comprising tubes U0 through U9, it will be apparent that each of the tubes is supplied from a source comprising a suitable battery B through a circuit comprising a pair of charging resistances RAi and RCi in series, Where i represents the number of the tube. In particular, a circuit extends from a suitable grounding point 1 through battery B and over positive bus or lead 2 through anode resistance RAO, from the plate to the cathode of tube U0, through cathode resistance RCO of tube U0, over lead 3, through winding TPK on saturable transformer TP, to be described and back to ground at 4-. The circuit for tube U1 extends from positive lead 2 through anode resistance RA1, between the plate and cathode of tube U1, through resistance RC1 to ground. Similarly, the circuit of tubes U2 through U8 include anode resistances RA2 through RA8 and cathode resistances RC2 through RAB connected between lead 2 and ground. Since these circuits are repetitive, it is believed unnecessary to describe each one in detail. The circuit of tube U9 extends from positive lead 2 through anode resistance RA9, between the plate and cathode of tube U9, through resistance RC9, over lead 5, and through winding TRK of saturable transformer TR, to be described, to ground at 6.

Each of the successive tubes U0 through U9 has its plate or anode connected to the plate of the preceding and succeeding tubes in the counting ring by capacitors CAi, where i represents the number of the stage. in particular, the plate of tube U0 is connected to the plate of tube U1 through capacitor CAO and the plate of tube U0 is also connected to the plate of the preceding tube, in this case U9 at the end of the chain, through capacitor CA9. The plate capacitances for the remaining tubes are identical with those just described and will not be further considered in detail. Further, the cathodes of each of the tubes in the chain are connected to preceding and succeeding cathodes through cathode capacitances CCi, where i is the number of the tube. For example, the cathode of tube U0 is connected to the oathodes of tubes U1 and U9 through capacitors CO0 and CC9, respectively. Since the other capacitors CCi are similarly connected, they will not be further described.

Each of the cathodes in the tubes of the counting ring are connected to the grids of succeeding tubes through rectifiers DPi. where z' is the number of the tube. For example, tube U0 has its cathode connected to the grid of tube U1 through rectifier DPO, the terminals of secondary winding UPll of transformer UP, to be described, and a grid resistor RG1. Similarly, the cathode of tube U1 is connected to the grid of tube U2 by connections including rectifier DPl, the winding of secondary UP2 on transformer UP, to be described, and grid resistance RG2. The cathode of tube U2 is connected to the grid of the succeeding tube, not shown, by a similar circuit including rectifier DP2. The remaining connections are the same as those just described, and it is believed unnecessary to describe them in further detail except to point out that the cathode of tube U9 is connected to the grid of tube U0 at the beginning of the chain by a circuit including rectifier DP9, the secondary winding UPO of transformer UP, to be described, and grid resistance RGO.

The cathodes of each of the tubes in the counting ring are also connected to the grids of preceding tubes in the chain by connections which will now be described. Beginning with tube U2, the cathode of this tube is connected to the grid of tube U1 through rectifier DRZ, the secondary winding URl of transformer UR, to be described, and grid resistance RG1. The cathode of tube U1 is connected to the grid of tube U0 through rectifier DRl, secondary winding URO on transformer 4 UR, and grid resistance RGO. The cathode of tube U0 is connected to the grid of tube U9 through rectifier DRO, secondary winding UR9 on transformer UR, and grid resistance RG9. The remaining tubes are similarly connected and these connections need not be further described.

The tens and hundreds decade counting chains are connected exactly as just described for the units decade except for certain differences in the initial and final tube circuits, as will now be described. First tube T0 in the tens decade counter has an operating circuit extending from positive bus 2 over lead 7, through anode resistance RA10, through tube T0, through cathode resistance RG10, over lead 10, and through winding HPK on saturable transformer HP, to be described, to ground at 11. A circuit for tube T9 extends from positive bus 2 over lead '7 through anode resistance RA19 and tube T9, through cathode resistor RC19, over lead 8, and through winding HRK on saturable transformer HR, to be described, to ground at 9. Similarly, tubes T1 through T8 are connected between positive bus 2 and ground by circuits including their anode resistances RA11 through RA18 and their cathode resistances RCll through RCIS.

Each of the cathodes of the tubes of the tens decade counter are connected to the grids of succeeding tubes by circuits including a rectifier, a secondary winding of an input transformer, and a grid resistance. For ex ample, the cathode of tube T0 is connected to the grid of tube T1 by a circuit including rectifier DP10, winding TP1 of transformer TP, and resistance RG11 to the grid of T1. The cathode of tube T9 is connected to the grid of tube T0 by a circuit including rectifier DP19, winding TPO of transformer TP and grid resistance RG10 to the grid of T0. The cathodes of the remaining tubes T1 through T8 are connected to their succeeding tubes by T2 through T9 by circuits including their associated rectifiers DP11 through DP10 and windings TF2 through TF8 on transformer TP, to be described.

The cathodes of each of the tubes of the tens decade counting chain are likewise connected to the grids of preceding tubes by connections including a rectifier, a winding of one of the input transformers, and a grid resistance. For example, the cathode of tube T0 is connected to the grid of tube T9 by a circuit including rectifier DR10, Winding TR9 of transformer TR and grid resistance RG19. The cathode of tube T9 is connected to the grid of tube T8 by a circuit including rectifier DR19, winding TRS of transformer TR, and grid resistance RG18. The cathodes of the remaining tubes T8 through T1 are similarly connected to their preceding tubes T7 through T0 by connections including their associated rectifiers DR18 through DR11, windings TR7 through TRO of transformer TR, and grid resistances RG17 through RG10.

The anodes of tubes T0 through T9 are interconnected by the anode capacitors CA10 through CA19, as shown. The cathodes of tubes T0 through T9 are also interconnected by capacitors CC10 through CC19, as shown.

The charging circuits for tubes H0 through H9 of the hundreds decade counting chain extend from positive bus 2, over lead 12, through the anode resistances of the tubes, from plate to cathode of each tube, and through the cathode resistances to ground. For example, the charging circuit for tube H0 extends from the positive terminal of battery 13 over bus 2 and lead 12, through anode resistance RA20, from the plate to the cathode of tube H0, and through cathode resistor RG20 to ground and to the negative terminal of battery B. Similar parallel circuits extend from lead 12 through anode resistances 11/121 through RA29, tubes H1 through H9, and cathode resistances RC21 through RC29 to ground.

The anodes of the succeeding tubes H0 through H9 in the hundreds decade are interconnected by capacitors CA20 through CA29, as shown. Similarly, the cathodes of tubes H0 through H9 are interconnected by capacitors CC20 through CC29, as shown.

The cathodes of the tubes H0 through H9 are connected to the grids of succeeding tubes in the ring by connections including a rectifier, a winding of a saturable transformer HP, to be described, and grid resistances RG20 through RG29. For example, the cathode of tube H0 is connected to the grid of tube H1 over a circuit including rectifier DP20, Winding HP1 of saturable transformer HP and grid resistance RG21. The cathode of tube H9 is connected to the grid of tube H0 over a circuit including rectifier DP19, winding HPO of saturable transformer HP, and grid resistance RG20. The remaining tubes have identical connections which need not be further described in detail.

The cathodes of each of tubes H0 through H9 are likewise connected to the grids of preceding tubes in the ring by connections including a rectifier, a secondary winding of saturable transformer HR, and the grid resistance previously described. For example, the cathode of tube H9 is connected to the grid of tube H8 by a circuit including rectifier DR29, winding HRS of transformer HR, and grid resistance RG28. Similarly, the cathode of tube Ht) is connected to the grid of tube H9 over a circuit including rectifier DRZiP, windingHR9 of transformer HR, and resistance RG29. The remaining circuits for the other tubes are identical and will not 'be further described.

As previously described, source'P comprises the source of progressive or adding pulses which serve to sequentially actuate the counting tubes of the counting chain for the various orders previously described. Source P has an output circuit including in parallel primary windings P1, P2 and P3 on transformers UP, TP and HP, respectively.

Transformer UP maybe of conventional construction, comprising primary winding P1, a conventional core, shown schematically, and a plurality of secondary windings UPO through UP9. These secondary windings are connected in the circuits of tubes U0 through U9, respectively, as indicated by showing the symbols for the windings at both the tube and transformer location. This convention was adopted to avoid showing the leads from the windings to the grid circuits of the tubes, since to show them would unnecessarily complicate the drawings. It will be apparent that upon the appearance of a puise at the output of source P, winding P1 of transformer UP is energized by a voltage which will induce a voltage in secondaries UP!) through UP9, and apply impulses to the grid circuits of tubes U0 through U9.

Transformer TP is a conventional saturable transformer and includes, in addition to primary winding P2 and secondary windings TPO through TP9, a saturating winding TPS and a desaturating winding TPK, for a purpose to be described.

Saturating winding TPS is energized by a circuit extending from ground at 1, through battery B, and through resistance 13 and the winding TPS to ground at 4. The number of turns on winding TPS is so selected that the core of transformer TP is saturated and, with reference to the magnetization curve of Fig. 2, will be sufiiciently beyond the saturation point so that the flux will substantially correspond to point A on the curve. This value is so chosen that a pulse appearing across primary winding P2 of transformer TP will only sufiice to bring the operating point of the core back to point B on Fig. 2, and no substantial change in flux density will occur. Accordingly, there will be no output on secondaries 'TPi) through TF9 in the presence of a pulse across P2 alone.

Additional winding TPK is provided to aid pulses appearing across primary P2 under certain conditions, to be described, so that the cumulative effect of windings TPK and P2 will bring the operating point of the core back to point C in Fig. 2, and the corresponding change in flux density in the core will induce an output voltage across secondaries TPO through TP9, which will be transmitted to the grid circuits of tubes T0 thro gh T9 by the connections shown.

Transformer HP is a saturable transformer substantially identical with transformer TP, just described. This transformer comprises a saturable core and a primary winding P3, a plurality of secondary windings HPO through HP9 connected in the grid circuits of tubes H1 through H9 as schematically shown, a saturating winding HPS, and an additional winding HPK.

Winding HPS is energized by a DC voltage over a circuit extending from ground at 1 through battery .B, resistor 14, and the winding of HPS to ground at 11'. The number of turns on the winding of HPS is selected to produce a magnetomotive force sufiicient to bring the core to a saturated value such as A in Fig. 2 as previously described in connection with transformer TP.

Winding HPK, acting under conditions to be described, at times aids winding P3 to overcome the efiect of winding HPS and bring the operating point of the core back to point C in Fig. 2, as described in connection with transformer TP, to permit an output pulse to appear across secondary windings HPO through HP9.

Source R of retrogressive or subtractive impulses for sequential operation of the counter tubes has parallel output circuits connected to primary windings R1, R2 and R3 on transformers UR, TR and HR.

Transformer UR is a conventional transformer identical in construction to transformer UP, previously described, and has a primary winding R1 and a plurality of secondary windings URO through UR9 connected, as indicated by the convention previously described, to the grid circuits of tubes U0 through U9. The leads connecting these windings to their respective grid circuits have not been shown, since to do so would unnecessarily complicate the circuit.

Transformers TR and HR comprise conventional saturable transformers identical with transformers HP and TP, previously described. These transformers have primary windings R2 and R3 and secondary windings TR9 and HRG through HR9, respectively. Each of the trans formers TR and HR also has a saturating winding TRS and HRS, respectively, transformer TRS being energized by a DC. voltage over a circuit extending from ground at 1, through battery B, over lead 2, through resistor 16, and through the winding of TRS to ground at 6. Winding HRS is energized by a DC. voltage over a circuit extending from ground at 1, through battery B, over lead 2, through resistance 15, and through winding HRS to ground at 9. Additional windings TRK and HRK cooperate at times to be described with primary windings R2 and R3 to idesaturate the core and produce output windings across secondary windings TRO through TR9 and HRO through HR9, respectively.

The operation of this embodiment of my invention will now be described. For this purpose, assume that tubes U9, T9 and H9 are conducting, which is the zero indicating condition of the apparatus.

Considering first the units decade chain, it will be apparent that the cathode of tube U0 will be above ground potential due to the drop through cathode resistor RCO. Accordingly, a positive voltage is transmitted through rectifier DPil, winding UPI, and grid resistor RG1 to the grid of tube U1, and a similar voltage is transmitted to the grid of tube U9 through rectifier DRO, winding UR9, and resistance RG9. Cathode resistances RCi, where i is the number of the stage, are so selected that this voltage is insufficient to cause tubes U1 and U9 to fire, but

the voltage thus supplied to the grids of U1 and U9 is a substantial part of the voltage necessary for firing. Accordingly, any additional voltage applied to the grids of either U1 or U9 will cause these tubes to conduct.

Now, assume that a progressive impulse is transmitted from source P and appears across primary Winding P1 of transformer UP. This voltage impulse will induce an impulse in secondary windings UPO through UP9. Considering secondary winding UP1, the half cycle or half cycles of this impulse which are effective act in the direction indicated by the arrowhead of the rectifier sym' bol DPO. If opposite half cycles occur, they will be ineffective because blocked by rectifier DPO and opposed by the cathode voltage of U0. The effective pulse in the direction of the arrowhead of the rectifier symbol D1 will add to the cathode voltage of U0 appearing through rectifier DPO and the cumulative voltage applied to the grid of U1 through resistor RG1 will be sufficient to fire tube U1.

Before considering the events occurring upon the conduction of tube U1, the action of the remaining primary windings UPO and UP2 through U1 9 will be considered. It will be seen that the impulse appearing across transformer secondary UP9 in the direction of the arrowhead of rectifier symbol DP8 is applied to the grid of U9 in parallel with the preparing voltage from the cathode of U0 which is supplied through rectifier DRO and winding UR9. Accordingly, this voltage will not substantially increase the voltage of tube U9 and this tube will not be fired. Of the remaining tubes, U0 is already conducting and tubes U2 through U8 will not be rendered conducting since the impulses appearing across windings UPZ and UPS will be insuflicient, in the absence of a preparing voltage from the cathode of an adjacent conducting tube, to render these tubes conducting. Accordingly, only tube U1 will be rendered conducting.

Upon the conduction of tube U1, the simultaneous lowering of the anode voltage due to the drop across resistor RAl and the raising of the cathode voltage due to the voltage drop across cathode resistor RC1 will be transmitted to the plate and cathode, respectively, of tube U0 through capacitor CAO and CCO. The simultaneous lowering of the plate potential of U0 and raising of its cathode potential will be effective to cut off tube U0 and it will be deenergized. Capacitors CA1 and CC1 similarly transmit impulses to the plate and cathode, respectively, of tube U2, but these impulses have no effect since tube U2 is already deenergized.

Due to the rise in cathode potential of tube U1, a positive preparing voltage is applied to the grid of tube U0 over a circuit including rectifier DRE, winding URO of transformer UR and grid resistor RGO. A similar preparing voltage is applied to the grid of tube U2 from the cathode of U1 over a circuit including rectifier DP1, winding UP2 of transformer UP and grid resistor RG2. U2 is therefore prepared for conduction upon the receipt of the next progressive pulse, whereas U0 is prepared for conduction upon the receipt of the next retrogressive or subtractive pulse.

The effect of the first progressive pulse on transformers TP and HP will be next considered. Windings TPS and HPS on these units maintain the flux densities in their respective cores in the saturation region as indicated by point A in Fig. 2. The progressive pulse applied to primary windings P2 and P3 on these transformers is sufficient to bring the flux density back to point B in Fig. 2, but is insufficient to cause any substantial change in flux in the core. Winding TPK on transformer T? is subject to a pulse of voltage as tube U0 ceases to conduct due to the counting action in the units decade as previously described. However, this pulse will be out of phase with the input pulse on winding P2 and hence does not effect a desaturation of the core of transformer TP. Accordingly, there is no output on the secondary windings TFO through T P9 of transformer TP and no change takes place in the tens decade counting chain. Since there is no change in the conducting states of tubes T0 through T9 in a tens decade counting chain, there will be no effect on winding HPK of transformer HP and there will therefore obviously be no output across secondary windings HPO through HP9. Accordingly, no change takes place in the hundreds decade counting chain.

Next, assume that tube U1 is conducting as previously dsecribed and a regressive or subtractive impulse is received from input pulse source R. This pulse input will be applied in parallel across primary windings R1, R2 and R3 of transformers UR, TR and HR, respectively. Since tube U1 is conducting, the grids of tubes U0 and U2 are prepared for causing these tubes to conduct upon the receipt of a suitable additional pulse. The preparing circuit for the grid of tube U0 extends from the cathode of U1 through rectifier DR1 and the winding of secondary URO of transformer UR as previously described. Accordingly, the impulse induced in secondary winding URO by primary winding R1 is applied in series with the preparing voltage from the cathode of U1 and tube U0 is caused to conduct. The pulse appearing across secondary winding URZ will be ineffective to render tube U2 conducting because this pulse acts in parallel with the preparing voltage, which is supplied by a circuit extending from the cathode of tube U1 through rectifier DP1 and winding UP2 on transformer UP, which is deenergized at this time. The remaining tubes will be unaffected by pulses appearing across the UR secondaries because their grids are not prepared.

As tube U0 goes into conduction, the change in current through its charging circuit causes a pulse to appear across winding TPK of transformer TP which is sufficient to bring the flux density in its core back to point B in Fig. 2. However, due to the absence of a progressive pulse across primary P2 at this time, there is no output across transformer TP.

The drop in plate voltage and rise in cathode voltage attendent upon the conduction of tube U0 are transmitted through plate capacitors CAO and CA9 and cathode capacitors CCO and CC9 to the plates and cathodes of tubes U9 and U1, respectively. Since tube U9 remains non-conducting, this pulse has no effect on its operation. However, the drop in plate voltage and rise in cathode voltage imposed on tube U1 causes this tube to cease conduction. The input pulse appearing across windings R2 and R3 of transformers TR and HR will be effective to return the flux densities of the cores of these transformers to point B in Fig. 2, but since there is no change in states of tubes U9 and T9, no impulses appear across windings TRK and HRK, respectively, and therefore there is no output across the secondaries of transformers TR and HR. No change, therefore, takes place in the tens and hundreds decade. The apparatus is accordingly returned to its initial state.

Next, assume that tube U9 in the units decade is conducting and that tubes T0 and H0 in the tens and hundreds decades are conducting, indicating 9. Now, assume that a progressive pulse is received from source P and appears across primary windings P1, P2 and P3. Since tube U9 is conducting, tubes U8 and U0 are prepared for conduction by the voltage applied from the cathode of tube U9 through the circuits previously traced to the grids of tubes U8 and U0. Due to the input pulse across P1, an output pulse appears across secondaries UPO through UP9 in transformer UP. It will be apparent from the preceding discussion that the pulse appearing across UPS will be in parallel to the preparing voltage to the grid of U8 supplied through rectifier DR9 and the winding UR8 of deenergized transformer UR. Accordingly, tube U8 will remain nonconducting. However, the impulse supplied to the grid of tube U0 through primary winding UPO will act in series with the preparing voltage supplied from the cathode of tube U9 through rectifier DP9. Accordingly, tube U0 will begin conduction.

The consequent rise in cathode potential on U0 will result in a change of current through winding TPK on transformer TP. Since this pulse is in a sense to aid the pulse appearing across primary winding P2, and since it appears substantially simultaneously with the input pulse 9 due to the rapid change in state of tubes U9 and U0, the flux density in transformer TP is brought back to point C in Fig. 2 and the consequent change in flux density causes an output pulse to appear across secondary windings TFO through TF9. Since tube T is conducting, the tubes T1 and T9 are prepared for conduction by the circuits previously described. The impulse appearing across winding TP1 will accordingly be effective to aid the preparing voltage supplied from the cathode of T0 through rectifier DP10 to cause conduction in tube T1. T1 will accordingly begin to conduct and will cut off tube T0 by the action of its plate and cathode coupling capacitances CA10 and CC10.

At the cessation of conduction in tube T0, a change in voltage appears across winding HPK of transformer HP which is opposite to the phase of the residue of the pulse on P3. Accordingly, no output will appear across secondaries HPO through HR9. The apparatus will accordingly be in equilibrium with tube T1 conducting and tubes U0 and H0 conducting, indicating 10.

Next, assume that a regressive or subtractive pulse is received from source R with tubes U0, T1 and H0 conducting. From the preceding discussion, it will be apparent that in the uni-ts decade counting chain tubes U1 and U9 will be prepared, in the tens decade tubes T0 and T2 will be prepared, and in the hundreds decade tubes H1 and H9 will be prepared. Tube T0 is prepared over a circuit extending from the cathode of tube T1 through rectifier DR11 and secondary winding T R0 of transformer TR. Accordingly, an input pulse appearing across TRO in series with rectifier DR11 will cause tube T0 to become conducting and cut off T1. Tube U9 is prepared by a circuit extending from the cathode of tube U0 over rectifier DRO and through winding UR9 on transformer UR. Since the regressive pulse appearing across R1 is applied directly to the secondary windings of UR, a pulse appears across UR9 adding to the preparing voltage and tube U9 becomes conducting, cutting off U0. As U9 becomes conducting, a pulse appears across TRK due to the circuit extending from the cathode of U9 through resistance RC9, and lead 5 through the winding of TRK to ground at 6. This pulse aids the pulse appearing across R2 from source R and there is therefore an output pulse across the secondary windings TRO through TR9. The pulse appearing across TRO adds to the preparing voltage from the cathode of T1 to fire T0 and cut off T1 by the circuit action previously described. This pulse has no effeet on either of prepared tubes H1 and H9 in the hundreds decade chain, since the pulse which appears across transformer R3 is not applied to the secondaries HRO through HR9 because winding HRK remains deenergized.

As an example, a transition from 100 to 99 will be described. Assume that tube U0 in the units decade, T0 in the tens decade, and H1 in the hundreds decades are conducting indicating 100. To indicate 99, tubes H0 :T9, and U9 must be rendered conductive and tubes H1, T0, and U0 must be cut off.

From the preceding discussion, it will be apparent that in the units decade counting chain tubes U1 and U9, in the tens decade counting chain tubes T1 and T9, and in the hundreds decade tubes H0 and H2 will be prepared. Tube H0 is prepared over a circuit extending from the cathode of tube H1 through rectifier DR21 and secondary winding HRO of transformer HR. Tube T9 is prepared over a circuit extending from the cathode of tube T0 through rectifier DR10 and through winding TR9 on transformer TR. Likewise tube U9 is prepared over a circuit extending from the cathode of tube U0 through rectifier DRO and through winding UR9 on transformer UR.

Assume that a regressive pulse is received from source R.

-' directly to the secondary windings of UR a pulse appears TRK due to the circuits extending from the cathode of tube U9 through resistence RC9, and lead 5 through the winding of TRK to ground at 6. This pulse appearing across TRK aids the pulse appearing across primary R2 from source R and there is, therefore, an output pulse across secondary windings TRO through TR9. Since T9 is prepared over the circuit described above, the pulse appearing across T R9 causes T9 to become conductive,

cutting off T0. Likewise, as tube T9 becomes conductive a pulse appears across HRK by way of the circuits extending from the cathode to tube T 9 through resistance RG19 and lead 8 through the winding of HRK to ground at 9. This pulse appearing across HRK aids the pulse appearing across primary R3 from source R and there is, therefore, an output pulse across secondary windings HRO through HR9. Since H0 is prepared over the circuit described above, the pulse appearing across HRO causes H0 to become conductive, cutting off H1.

The pulses appearing across secondary winding HRZ will be ineffective to render tube H2 conducting because this pulse acts in parallel with the preparing voltage which is supplied by the circuit extending from the cathode of tube H1 through rectifier DP21 and winding HPZ on transformer HP, which transformer is not energized at this time.

Likewise, the pulses appearing across secondary winding TR1 will be ineffective to render tube T1 conductive.

It is believed that the specific examples of operation just described will be sufficient to indicate to those skilled in the art the operation of the disclosed apparatus under any other operating condition. Obviously, in infinite variety of input conditions could occur, but in each case the application of a progressive or regressive pulse causes the tubes which are ahead of or behind the previously conducting tube in the chain, respectively, to be energized and to cut off the previously conducting tube. Further, as each order chain completes a counting cycle by firing its tube 0 and cutting off its tube 9, the next higher order decade input transformer is activated to permit the transmission of a pulse to a tube in that chain. Also as each regressive cycle is begun in a given chain by cutting off its tube 0 and firing its tube 9, the pulse transformer for the next higher order chain is prepared for the reception of a regressive pulse to step back one counting unit. As examples of each of these events have been given, it is believed unnecessary to further describe the operation of the circuit.

Although I have shown an embodiment of my invention based on the decimal numbering system and showing three counting decades, it will be apparent to those skilled in the art that any numbering system could be used as a basis for an embodiment of my invention, in which case the number of tubes in each order counting chain would equal the number of signs for each order in that numbering system, and that any numbering system, and that any number of orders could be provided depending upon the range over which it was desired to count. Further, while I have shown only one embodiment of my invention in detail, other changes and modifications will be apparent to those skilled in the art upon reading this descrip tion, and I accordingly do not wish to be limited to the details shown, but only by the scope of the following claims.

Having thus described my invention, what I claim is:

1. A reversible counting chain, comprising, in combination, first and second order counting rings comprising a first and second plurality of electron discharge devices, each device having an anode, a cathode and a control electrode, successive anodes of the devices of said rings being capacitively coupled, successive cathodes of the devices of said rings being capacitively coupled, whereby upon conduction of a given device preceding and succeeding adjacent devices which may be conducting are cut oil, unidirectionally conducting means connecting each of said cathodes to the control electrodes of the preceding and succeeding devices in its ring, whereby upon conduction of a given device, a priming voltage is transmitted to the control electrodes of preceding and succeeding devices, a first transformer for each ring having a secondary winding for each device of the ring and a primary winding adapted to be energized by a counting voltage pulse, each of said secondary windings being connected in series with corresponding ones of said unidirectional conducting means between the control electrode of a device and the cathode of the preceding device, whereby upon receipt of a counting voltage pulse during the conduction of a given device the control electrode of the succeeding device receives said priming voltage in series with said pulse and said succeeding device is caused to conduct, a second transformer for each ring having a secondary Winding for each device and a primary winding adapted to be energized by a subtracting voltage pulse, each of said secondary windings being connected in series with corresponding ones of said unidirectional conducting means between the control electrode of a device and the cathode of the succeeding device, whereby upon receipt of a subtracting voltage pulse during the conduction of a given device the control electrode of the preceding device receives said priming voltage in series with said subtracting pulse and said preceding device is caused to conduct, said first and second transformers for said second ring having saturable cores, first additional Windings on said saturable cores adapted to be energized by a voltage sufiicicnt to saturate said cores regardless of the presence of a voltage pulse on said primary windings, second additional windings on said saturable cores, means coupling the cathodes of first and second adjacent devices in said first ring to said first and second transformers of said second ring, respectively, so that upon receipt of a counting pulse causing conduction of said first device a pulse is applied to said second additional winding on said core of said first transformer or" said second ring of a value sufficient, in the presence of said counting pulse, to desaturate said core and produce an output pulse on said secondary windings, and so that upon receipt of a subtracting pulse causing conduction of said second device a pulse is applied to said second additional winding on said core of said second transformer of said second ring of a value sufiicient, in the presence of said subtracting pulse, to desaturate said last mentioned core and produce an output pulse on its secondary windings, whereby said first ring will complete one cycle of operation for each step of operation of said second ring.

2. A reversible counting chain, comprising, in combination, a plurality of counting devices arranged in an order of precedence from a first to a last device, each device having a control circuit and a load circuit, said load circuit having an energized or a non-energized state in accordance with the state of said control circuit, means coupling the load circuit of each device to the load circuits of preceding and succeeding devices, including couplings between the load circuits of said first and last devices, said couplings being efiective upon the energizetion of a given load circuit to deenergize a preceding or succeeding load circuit which may be energized, nonlinear coupling means connecting the load circuit of each device to the control circuit of preceding and succeeding devices, including couplings between the load and control circuits of said first and last devices, said non-linear coupling means being effective in the energized state of a device to prepare the control circuits of preceding and succeeding devices for changing the state of the load circuits of said last mentioned devices upon the receipt of a counting pulse, means for applying progressive counting pulses simultaneously to the control circuits of said devices in series with the non-linear coupling means between the load circuits of said devices and the preceding control circuits, and means for applying retrogressive counting pulses simultaneously to the control circuits of said devices in series with the non-linear coupling means between the load circuits of said devices and the succeeding control circuits.

3. In a reversible counting device, in combination, a first counting chain comprising a plurality of devices including a first and last device, said devices being sequentially operable in a first sense in response to progressive counting pulses applied thereto and sequentially operable in a reverse sense in response to retrogressive counting pulses applied thereto, means for applying progressive counting pulses to said devices, means for applying retrogressive pulses to said devices, a second counting chain comprising a plurality of devices sequentially operable in a first sense in response to progressive counting pulses applied thereto and sequentially operable in a reverse sense in response to retrogressive counting pulses applied thereto, first transformer means responsive to operation of said first device by a progressive pulse for applying said pulse to said second chain, and second transformer means responsive to operation of said last device by a retrogressive pulse for applying said retrogressive pulse to said second chain.

4. Reversible counting apparatus for counting over a predetermined number of orders of magnitude in a selected number system, said apparatus having for each order of magnitude a counting ring of electron discharge devices equal in number to the number of signs for each order in said number system, said devices having anodes, cathodes, and control electrodes, capacitive connections between adjacent anodes and between adjacent cathodes of said devices, first non-linear impedance means and a first coil connected in series between each cathode and the control electrode of the preceding discharge device, second non-linear impedance means and a second coil connected in series between each cathode and the control electrode of the succeeding discharge device, first means for applying voltage pulses in parallel to said first coils, second means for applying voltage pulses in parallel to said second coils, blocking means for each order of magnitude higher than the first for rendering said first and second pulse applying means ineffective, means responsive to conduction of the last device in a given order ring for overcoming the effect of said blocking means on said first pulse applying means in the suc ceeding order ring, and means responsive to conduction of the first device in a given order ring for overcoming the effect of said blocking means on said said second pulse applying means in the succeeding order ring, whereby each order ring completes a cycle of operation for each step of operation of the succeeding order ring.

5. In a counting device for reversibly counting over a predetermined number of orders of magnitude in a number system having a predetermined number of signs for each order of magnitude, a number of electron tubes for each order equal to said number of signs, each tube having an anode circuit, a cathode circuit, and a grid circuit, a source of direct voltage, two series charge resistances for each tube, one in the anode circuit and one in the cathode circuit, said anode and cathode circuits being connected to opposed terminals of said source whereby all of the tubes are fed from said source, anode capacitors located between anodes of consecutive tubes, cathode capacitors located between cathodes of consecutive tubes, preparation elements for applying to each grid circuit a potential forming an essential part of the 13 amplitude necessary to start each tube, and pulsing elements for applying an impulse to said grid circuits, the impulses from said pulsing elements co-operating with the potential applied to said grid circuits to successively control the progression or retrogression of the device.

6. A device as recited in claim 5, in which the preparation elements comprise members of asymmetric conductivity connected in an opposite way with respect to each other in each of the connections between cathodes and grids of successive tubes.

7. A device as recited in claim 5, in which the pulsing elements comprise windings connected in series with the connections between cathodes and grids, and in which these windings form independent secondaries of impulse transformer means fed by means for generating progressive or retrogressive impulses.

8. A device as recited in claim 5, further comprising a pair of magnetic circuits for each order of magnitude higher than the first, said circuit comprising a first winding fed in a permanent manner and bringing the point of operation of said circuit to rest in saturation, a second winding for each circuit, one of said second windings fed by a generator of progressive impulses and the order of said second windings fed by a generator of retrogressive impulses, a third winding in one of said circuits in series in the cathode circuit of the first tube of the series of tubes corresponding to the order of the magnitude under consideration, and a third Winding in the other of said circuits in series in the cathode circuit of the last tube of the series of tubes corresponding to the order of magnitude under consideration, said previously recited pulsing elements for orders of magnitude higher than the first comprising a series of independent secondary windings in said magnetic circuits.

9. In a driving circuit for a reversible counting device having a plurality of reversible counting chains representing successive orders of magnitude in a predetermined number system, in combination, first and second transformers for sequentially actuating the first order chain, said transformers having a primary winding and output winding means, first pulsing means for applying progressive impulses to the primary winding of said first transformer, second pulsing means for applying retrogressive impulses to the primary Winding of said second transformer, means connecting the output winding means of said first transformer to sequentially actuate said first order chain in a progressive sense, means connecting the output winding means of said second transformer to sequentially actuate said first order chain in a retrogressive sense, first and second magnetic circuit means for each order higher than the first for sequentially actuating the higher order chains, said circuits comprising a saturable core having a primary winding and output winding means, a first additional winding on each core adapted to be energized by a voltage exceeding by a predetermined amount the voltage necessary to saturate said core, a

second additional winding on the core of said first magnetic circuit responsive to completion of a progressive cycle of operation of the next lower order chain for applying a voltage suflicient to nullify part of said predetermined amount of voltage, a second additional winding on the core of said second magnetic circuit responsive to the beginning of a retrogressive cycle of operation of the next lower order chain for applying a voltage suflicient to nullify part of said predetermined amount, said primary windings for said first magnetic circuits being connected in parallel to said first pulsing means, said primary windings for said second magnetic circuits being connected in parallel to said second pulsing means, said primary windings being effective when pulsed to apply a voltage to said cores suificient in the presence of a voltage from said second additional windings to desaturate said cores and apply impulses to said output winding means, said output winding means for said first magnetic circuits being connected to corresponding higher order chains for progressive sequential operation thereof, and said output winding means for said second magnetic circuits being connected to corresponding higher order chains for retrogressi've operation thereof.

10. Apparatus of the class described, comprising, in combination, first and second impulse generators for supplying progressive and retrogressive counting impulses, respectively, a plurality of sequentially operable counting chains arranged to correspond to successive orders of magnitude, pulse transmitting means for each chain for applying impulses from said first and second impulse generators to said chains to efiect sequential operation thereof in a progressive or retrogressive sense in accordance with energization of the first or second generator, transformer means for each pulse transmitting means but those corresponding to the first order chain for blocking the transmission of impulses, transformer means connected to each chain and responsive to completion of a progressive cycle of operation for rendering said blocking means for the next higher order chain ineffective to block a progressive impulse, and transformer means connected to each chain and responsive to the beginning of a retrogressive cycle of operation for rendering said blocking means for the next higher order chain inefiective to block a retrogressive impulse.

References Cited in the file of this patent UNITED STATES PATENTS 2,500,294 Phelps Mar. 14, 1950 2,533,739 Mumrna Dec. 12, 1950 2,534,287 Marsh Dec. 19, 1950 2,539,623 Heising Jan. 30, 1951 2,542,644 Edson Feb. 20, 1951 2,656,460 McMillan Oct. 20, 1953 2,727,683 Allen et al Dec. 20, 1955 2,750,114 Crosman June 12, 1956 

